Ischemia

(redirected from silent ischemia)
Also found in: Dictionary, Thesaurus, Medical.
Related to silent ischemia: silent myocardial ischemia

ischemia

[i′skē·mē·ə]
(medicine)
Localized tissue anemia as a result of obstruction of the blood supply or to vasoconstriction.

Ischemia

 

a local deficiency of blood; insufficient blood in an organ or tissue because of the narrowing or complete occlusion of the lumen of an afferent artery.

Transitory ischemia (like hyperemia) may result from physiological regulation of the blood supply, such as in reflex spasm of an artery caused by a mental factor (fright); the influence of pain, cold, chemical substances (epinephrine, ergotin), and biological stimuli (bacteria, toxins); the obstruction of an artery by a thrombus or embolus; constriction of the lumen of a blood vessel in connection with an atherosclerotic or inflammatory process in the wall; or compression of an artery by a tumor, scar, or foreign body. The aftereffects of ischemia depend on the degree of disruption of the blood flow, the rate of development and duration of the ischemia, the sensitivity of the tissue to oxygen deficiency, and the general condition of the body. Ischemia may end in complete restoration of the structure and function of the affected organ or tissue, but it also may lead to necrosis (infarct). The central nervous system and heart muscle are particularly sensitive to ischemia.

N. R. PALEEV

References in periodicals archive ?
Previous studies suggested that the prevalence of silent ischemia in hypertensive diabetic patients varied from about 15% to over 50%.
Patients and clinicians might be more likely to address risk factors for cardiovascular disease in patients with silent ischemia.
409); elevated concentrations of heart-stimulating hormones; and increased incidence of silent ischemia, a temporary, often painless reduction of blood flow to the heart (SN: 11/25/89, p.
The study will include 35 patients with diagnosed stable and unstable angina or documented silent ischemia, with angiographic and intravascular ultrasound (IVUS) follow-up at 6 months to measure the percent in-stent volume obstruction.
In the Detection of Ischemia in Asymptomatic Diabetics (DIAD) study of 1, 123 patients with type2 diabetes, CAN was a strong predictor of silent ischemia and subsequent cardiovascular events.
For example, the DIAD (Detection of Ischemia in Asymptomatic Diabetics) study showed that basing the decision to screen on clinical features alone would fail to identify 41% of patients with silent ischemia (Diabetes Care 2004;27:1954-61).
Beta blockers are used primarily to help control atrial fibrillation and are also given to patients after a heart attack, but the study, led by Cleveland Clinic cardiologist Ilke Sipahi, MD, supports the long-term use of beta blockers in patients with conditions such as silent ischemia, stable or unstable angina, and asymptomatic coronary disease.
About half the patients had unstable angina, about 40% had stable angina, and the remainder had silent ischemia.
If studies confirm that suspicion, the implications may extend beyond silent ischemia.
The interrelated systems lead to a state of myocardial ischemia that produces angina pectoris, silent ischemia, or myocardial infarction.